This invention relates generally to nanomanipulation and, more particularly, to nano-orientation of antibody-dendrimer conjugates. The compositions of matter and methods of the present invention allow one to construct more sensitive bioassays by improving the orientation of the antibody binding domains within the bioassay at the nanoscopic level.
This invention deals with nanomanipulation and, more particularly, nano-orientation of antibody-dendrimer conjugates to construct more sensitive and accurate immunoassays. These improved bioassays are more reproducible with virtually no false positive or false negative responses. In addition, this invention also reduces the amount of reagent used in the immunoassays, thus reducing the production and operating costs. Finally, the present invention provides the capability of using nanomanipulation to construct miniaturized nanodevices for chemical/biological (chem/bio) sensor applications.
Due to rapidly growing demands in market sectors such as medical diagnostics, high-throughput drug/gene screenings, environmental monitoring, chemical and biological defense, and domestic preparedness programs (chemical-biological antiterrorism); the development of miniaturized chem/biosensors has recently become an important RandD focus in industrial, government, and academic laboratories. Currently, most of the hospital medical diagnostic assays, combinatorial drug/gene screenings, and environmental monitoring methods are primarily based on bulky instruments such as flow cytometry, Threshold, and Origin devices. These instruments, although very sensitive, are often not suitable for environmental monitoring or domestic counter-terrorist programs due primarily to the difficult field operating conditions. Nor are they useful for home medical diagnostics because of the restrictive nature of home testing conditions. For example, dirty environmental samples often complicate the assay results, and limited power supplies in the field generate additional logistic problems. The requirement of well-trained personnel to carry out the assays also poses many practical problems for using these instruments both at home and in the field. Conversely, the high-throughput drug and gene screening industry prefers fast, sensitive, low cost, and more importantly, miniaturized sensors that only require a very small amount of sample, and are capable of detecting extremely low levels of active components.
Recently, a number of research groups have attempted to use microelectrical mechanical systems (MEMS) technology to xe2x80x9cshrinkxe2x80x9d the existing detectors or analytical instruments through a xe2x80x9clab on a chipxe2x80x9d approach. This approach utilizes microlithograghy techniques (borrowed from the microelectronic industry) to produce micron sized microfluidic cells that can perform both separation and detection at the same time. As a result, the size of the current instrument hardware could be miniaturized very dramatically, and the cost could also be significantly reduced. However, these instruments are still in development and commercial devices are not available. Moreover, this xe2x80x9ctop-downxe2x80x9d approach only addresses problems down to about the one-micron level. Since most of the biological sensing events occur at nanoscopic level (1000 times smaller), the performance of these assays will at most remain the same as their bulky instrument counterparts. Therefore, the manipulation of these binding events at nanoscopic size scale is not only more important, but also more challenging for the further advancement of this miniaturization. In this patent we will disclose a novel nanomanipulation approach to constructing miniaturized nano-biodetectors with superior assay performance.
International patent application WO 95/24221 PCT/US95/03045 and U.S. Pat. No. 5,714,166 entitled xe2x80x9cBioactive and/or targeted Dendrimer Conjugatesxe2x80x9d disclose dendrimer related conjugates, however, neither of them deals with nanomanipulation and nano-orientation. Furthermore, the chemical structure of the dendrimers disclosed in these references is unlike that of the present invention. International patent application WO 95/28641 PCT/US95/04313 xe2x80x9cRapid Detection of Analytes with Receptors Immobilized on Soluble Submicron Particles,xe2x80x9d and WO 95/27902 PCT/US95/04547 xe2x80x9cRandom Detection of Antigens with Antibodies Immobilized on Soluble Submicron Particles,xe2x80x9d and PCT/US/96/13057 WO 97/07398 xe2x80x9cPolypeptide-Dendrimer Complexesxe2x80x9d also disclose using dendrimer-antibody conjugates for immunoassays. However, all of these assays are bulky instrument-based assays. Moreover, none of the above disclose the dendrimer structure of the present invention in that the present invention utilizes specific exterior surface functional groups in the dendrimer in order to tailor the dendrimer-ligand a conjugate so that it is self-orienting on a surface. For example, exterior surface functional groups including both amine and hydroxyl groups have been found particularly effective for the nanomanipulation concept, especially in a miniaturized hand-held, visual detection format.
Accordingly, it is a primary object of the present invention to provide compositions of matter and methods using nanomanipulation to improve the performance of bioassays.
It is a further object of the present invention to provide methods of using nanomanipulation to construct miniaturized biodetectors or nanodevices.
It is another object of the present invention to use these nanomanipulation methods to enhance bioassay performance, as well as reducing reagent cost and false positive responses.
The foregoing and other objects and advantages of the present invention will hereafter become more fully apparent from the following detailed description. In the description, reference will be made to examples and drawings which form a part hereof, and in which is shown by way of illustration, and not limitation, certain preferred embodiments. Such description does not represent the full extent of the invention, but rather, the invention may be employed according to the full scope and spirit of the invention as defined in the appended claims.